Medical or dental treatment chair

ABSTRACT

The invention relates to a medical or dental treatment chair ( 1 ) having a seat part ( 2 ), a back part ( 4 ), a carrier part ( 16 ) arranged on the back part ( 4 ), an intermediate lever ( 23 ) which with its one end is pivotably connected with the carrier part ( 16 ), a head support lever ( 24 ) which with its one end is pivotably connected to the other end of the intermediate lever ( 23 ) and carries a head support pad ( 21 ), and an intermediate lever adjustment motor (M 3 ) which is effective between the carrier parts ( 16 ) and the intermediate lever ( 23 ). For the support function there is provided a head support lever adjustment motor (M 4 ) which is effective between the intermediate lever ( 23 ) and the head support lever ( 27 ).

RELATED APPLICATION DATA

The present patent is a National Stage of international applicationPCT/EP01/03270, filed on Mar. 22, 2001.

FIELD OF THE INVENTION

The invention relates to a medical or dental treatment chair having ahead support which is adjustable in consideration of differenttreatments of the patient.

BACKGROUND OF THE INVENTION

It is known to provide for such an adjustment at least one motorizeddrive which is associated with the head support. In the case of amotorized drive, the head support is positioned in the adjusteddisposition, against an unintended movement, due to the self-locking ofthe motorized drive. For the purpose of reducing the mechanical outlaythere have, however, also been developed manually operable adjustmentdevices for the head support. With this it is necessary to fix the headsupport in the respective adjusted position, against an unintendeddisplacement, by means of a fixing device. With regard to the state ofthe art attention is directed to DE 82 07 541 U1, DE 296 20 801 U1, EP 0701 806 A1 and EP 0 673 633 A2.

A treatment chair of the kind indicated in the preamble of claim 1 isdescribed in DE 29 32 345 A1. With this known treatment chair, a headsupport is connected in a middle position by means of a base joint withthe free end of a telescopic support part which at its other end ispivotably connected by means of a joint with a backrest of the treatmentchair. For pivoting the telescopic support part in its base joint thereis provided a piston-cylinder unit which is jointed on to the backrestat a radial spacing from the base joint and engages in a jointed mannerwith its other end at the forward end of the telescopic support part.There is associated with the telescopic support part a latching devicewhich makes it possible selectively to latch the telescopic supportparts to one another or to release them. The base joint can beselectively locked or released with a second latching device. With thisknown treatment chair it is possible, depending upon the actuation ofthe first or second latching device, to extend or retract the headsupport by means of an appropriate actuation of the piston-cylinder unitor to pivot the head support around the joint axis of the base joint,the head support itself being freely pivotably in the joint connectingit with the telescopic support part. This known configuration is complexboth with regard to construction and also operation. Further, thesupport function is unsatisfactory.

SUMMARY OF THE INVENTION

The present invention is based on the object of improving the supportfunction of a treatment chair. Further, a simple construction andoperability are to attained.

With the configuration in accordance with the invention both theintermediate lever and also the head support lever are each purposelyadjustable by means of the associated adjustment motor, the head supportlever, whilst providing a large adjustment range, taking up a stableposition. Due to the positioning of the head support lever in theoverall large adjustment range, the reliability of support for thepatient is improved. The adjustment of the head support may be effectedby means of switching on of the adjustment motors successively orsimultaneously. In the latter case, the adjustment time can also beconsiderably reduced.

For the configuration in accordance with the invention, adjustmentmotors of elongate or rod-like construction are particularly suitablesince they can be mounted or integrated on the associated lever, with asmall and spatially economic construction. By these means, theadjustment range of the head support lever can be better exploited andthus increased. Linearly acting adjustment motors are suitable whichwith their one end engage or are supported jointedly, at a workingdistance from the pivot axis of the associated pivot joint, pivotally onthe one joint part and on the other joint part. The operating effort foradjusting the head support pad is slight since the operating personsolely needs to actuate a respectively associated control element or acommon control element in order to switch on or switch off the desiredadjustment motor or motors. It is also possible to so configure anassociated control device that certain support dispositions of the headsupport pad are self-actingly assumed after switching on of theadjustment motor or motors in accordance with a program. By these meansthe operating effort is further reduced. It is particularly advantageousif the control device is so configured that the operating person can socontrol the control device that an individual adjustment of the headsupport pad is possible by means of an appropriate control through theoperating person or there is possible an adjustment of the head supportpad in accordance with the program.

The invention further has the object of improving a treatment chair withregard to its suitability for children.

The head support can be adjusted to a position in which it forms alargely transition-free continuation of the shell base of the back part.This position distinguishes itself as a particularly advantageous childposition, since it is well suited for children not only with regard toits slight spacing from the seat part but also because of its aligneddisposition with regard to the backrest, and ensures an advantageous andsecure support of the head of the child. Thereby, the support surface ofthe head support may likewise be formed to be trough-shaped whereby itneed not extend in this form over its entire length. The trough-shapedform of the support surface need extend only over a part length of thehead support towards the back part. In the end region of the headsupport away from the back part the trough may be bounded by atransversely running, in particular rounded, swelling into which thetrough changes preferably in an inclined or rounded manner.

BRIEF DESCRIPTION OF THE DRAWINGS

Below, the invention and further advantages which can be achievedthereby will be described in more detail with reference to preferredconfigurations. There is shown:

FIG. 1 a treatment chair in accordance with the invention, in a sideview;

FIG. 2 a back part or a backrest and a head support of a treatmentchair, in a perspective view from above;

FIG. 3 the head support of the treatment chair, in an enlargedillustration in a side view;

FIG. 4 the head support in a somewhat enlarged illustration and in itspivoted out support disposition;and

FIG. 5 the head support of FIG. 3 in a fully pushed down disposition.

DETAILED DESCRIPTION OF THE DISCLOSED EMBODIMENTS

The main part of the medical or dental treatment chair, designated inits entirety by 1, are a seat part 2, preferably adjustable in positionin the vertical longitudinal middle plane E of the chair, having a legsupport 3, a backrest 4, which is connected at the rearward end of theseat part 2 by means of a backrest joint 5 having a horizontal jointaxis extending transversely of the treatment chair 1, and which isadjustable around the joint axis between an upright sitting position andan approximately horizontal lying position by means of a firstadjustment device not shown in detail, and is fixable in the respectiveadjusted position by means of a first fixing device, and a head support7 having a base body 8, which is adjustably mounted on the backrest 4 bymeans of one or two carrier rods 9 running in the longitudinal directionof the backrest 4 and forming a carrier part. A first adjustable carrierfor treatment instruments 13 is designated by 12, which treatmentinstruments will primarily be used by the dentist, and a secondadjustable carrier part for treatment instruments 15 is designated by14, which treatment instruments will primarily be used by an assistant.

The carrier rods 9, extending in the longitudinal direction of thebackrest 3, which are adjustably connected with the backrest 3, form ahead support carrier part 16. The head support 7 is adjustable on thiscarrier part by means of a pivot device 17, in the vertical longitudinalmiddle plane E of the treatment chair 1, and is held fixably in therespective pivot position by means of a second fixing device designatedin its entirety by 19, in order to adjust the head support 7 with a pad21 arranged on its forward or upper side in a desired support positionwith regard to the head of a patient. A so-formed second adjustmentdevice is designated in its entirety by 22.

The backrest 4 consists of a back base part 4 a which is connected withthe backrest joint 5 by means of joint parts 5 a illustrated only inFIG. 1, and a backrest part 4 b which is occupied by a preferablyshell-shaped backrest pad 4 c. Between the back base part 4 a and thebackrest part 4 b there is formed a schematically illustrated guide 6 inwhich the backrest part 4 b is displaceable back and forth on the backbase part 4 a in the longitudinal direction of the backrest 4. For theadjustment there is provided a first adjustment motor M1, preferably ina rod-like construction which with its one end, here the end towards thebackrest joint 5, is supported on the back base part 4 a and with itsother end, here the end away from the backrest joint 5, engages on thebackrest part 4 b. For connecting the adjustment motor M1 with the backbase part 4 a and the backrest part 4 d there are provided on theseparts fixed mounting parts L1, L2. The adjustment motor M1 preferablyhas an electric motor E1 with which there is associated a transmissionG1 which transforms its rotating movements into a longitudinal movement.Here, there is preferably involved a spindle drive, the spindle of whichis designated by S1. Between the electric motor E and the transmissionG1 there may be provided a reduction gear unit G1 a.

The carrier part 16 is mounted to be displaceable back and forth bymeans of a second adjustment motor M2 in a second longitudinal guide 11arranged in the backrest part 4 b, in the longitudinal direction of thebackrest 4. The carrier part 16 is preferably formed by means of a flatslider arranged transversely to the vertical longitudinal middle planeof the treatment chair 1, in order to ensure a flat construction of thebackrest 4. The first adjustment motor M1 is located on the one sideneighbouring the carrier part 16, while the second adjustment motor M2is arranged on the other side neighbouring the carrier part 16. Thesecond adjustment motor M2 is also of rod-shaped or elongate structure,and it has preferably an electric motor E2 which is connected with thecarrier part 16 by means of a transmission G2 which transforms itsrotary movement into a straight line movement. The conversiontransmission G2 is in the exemplary embodiment likewise formed by meansof a spindle drive, the spindle of which is designated by S2.

The longitudinal guide 11 for the carrier part 16 is formed by means oftwo guide rods 11 a, 11 b arranged laterally next to the carrier part16, on which guide rods the carrier part 16 is held and guided withrunning bushes 11 c, 11 d attached to the carrier part at the sides. Inthe exemplary embodiment, the guide rod 11 b arranged near the secondadjustment motor M2 is formed as spindle S2, which stands in a screwconnection with the running bush 11 d formed as a spindle motor. Theadjustment motors M1, M2 are arranged outwardly of the running bushes 11c, 11 d. The second adjustment motor M2 is connected with the spindle S2by means of a belt drive, in particular a toothed belt drive.

The pivot device 17 has an intermediate lever 23 which at its one end isconnected, pivotably in the vertical longitudinal middle plane, with thecarrier part 16 by means of a first joint 24, and is connected at itsother end, pivotably in the vertical longitudinal middle plane, with ahead support lever 27 by means of a second joint 25. The intermediatelever 23 extends from the first joint 24 in an associated pivot range insubstance in the direction away from the backrest 4. The head supportlever 27 is located on the side of the intermediate lever 23 towards thehead of a patient located on the treatment chair 1, whereby theintermediate lever 23 and the head support lever 27 are pivotable in thepivot ranges which can be understood from the Figures, in which theyextend parallel to one another or enclose between them a small acuteangle which is open in the direction towards the backrest 4 (FIGS. 1 and3) or enclose a larger acute angle open towards the backrest 4 (FIG. 4).The second joint 25 is preferably arranged at the rearward end of thehead support lever 27 so that this lever in this case extends from thesecond joint 25 in the direction towards the backrest 4 and thus theends of the levers 23, 27 away from the backrest 4 terminateapproximately with one another. The backrest pad 21 is located on theside of the head support lever 27 away from the intermediate lever 23.

The intermediate lever 23 and the head support lever 27 are each aso-called wide lever, i.e. it consists of two lever webs 23 a, 27 ahaving a horizontal spacing from one another and arranged on edge, ofwhich the intermediate lever 23 or both levers are stabilized to a rigidlever component by means of a transverse part 23 b preferably arrangedat the upper edge, whereby the ends of the lever web 23 a may extendfreely standing away from the transverse part 23 b. The lever web 27 aof the head support lever 27 may be stabilized by means of a plate-likebase part of the base part carrying the head support pad 21, which ispreferably releasably attached to the head support lever 27, inparticular can be clipped on or clipped off by means of exercise ofmanual pushing and pulling force. For this purpose there may serve oneor more press-stud connections, which for reasons of simplification arenot shown.

The intermediate lever 23 is selectively pivotable back and forth in thefirst joint 24 by means of a third adjustment motor M3 effective betweenthis lever and the carrier part 16. The head support lever 27 isselectively pivotable back and forth in the second joint 25 by means ofa fourth adjustment motor M4 effective between the head support leverand the intermediate lever 23. The adjustment motors M3, M4 havepreferably an elongate or rod-like structure which is linearly effectivein their longitudinal direction and form push and pull rods thelongitudinal direction of which is substantially directed in thelongitudinal direction of the associated lever 23, 27. The adjustmentmotor 113 associated with the intermediate lever 23 is pivotallysupported, in the pivot plane, on the carrier part 16 transverselyoffset by an offset amount V1 with reference to the joint axis 24 a ofthe joint 24, whereby its other end engages likewise pivotably on theintermediate lever 23 at a greater working distance from the joint 24,preferably engaging in the second joint 24. The offset amount V1 ispreferably directed to the side away from the head support guide 27. Theadjustment motor M4 associated with the head support guide 27 isjointedly supported on the intermediate lever 23 transversely offset byan offset amount V2 with regard to the joint axis 25 a of the secondjoint 25, whereby its other end is jointedly connected with the headsupport lever 27 at a greater working distance from the joint 25,preferably connected in its end region towards the backrest 4. The headsupport lever 27 is preferably an angled lever having a transverselyrunning lever arm 27 c which in its end region associated with thesecond joint 25 stands away in an angled or curved manner and isconnected at its free end in the second joint 25 with the intermediatelever 23. The intermediate lever 27 has in its end region towards thesecond joint 25 a transversely upstanding lever arm 23 c which extendsto the side towards the head support pad 21 and is jointedly connectedwith the associated end of the adjustment motor M4. The connectionpoints for the adjustment motors M3, M4 are preferably formed by meansof joints 31, 32, 33 with joint bolts which each pass through a jointpart of the parts to be connected with one another in joint eyes. In thecase of the exemplary embodiment having the above-described wide leversthere are present in each case lever arms 23 c, 27 c having a transversespacing from one another, which may be formed by extensions of the leverwebs 23 a, 27 a. The adjustment motors M3, M4 are preferably arrangedbetween the lever webs 23 a, 27 a, whereby there can be attained a slimor low profile construction. The length of the adjustment motors M3, M4may correspond in substance to the length of the levers 23, 27.

The adjustment motors V3, V4 may be formed by means of hydraulic orpneumatic piston-cylinder units, or my have electric motors E3, E4, witheach of which there is associated a transmission G3, G4 transformingtheir rotary movement into a longitudinal directed movement, preferablya spindle drive the spindle S3, S4 of which may form a part of the twotelescopic adjustment motor parts.

For switching on and switching off the adjustment motors M1 to M4 thereis associated therewith in each case a non-illustrated switch element,e.g. on a control apparatus or foot switch, with which the operatingperson can selectively switch on and off the adjustment motors M3, M4.For example for an adjustment individually controllable by the operatingperson or for a position in accordance with a predetermined program.

The head support 7 has a shell or trough-shaped head support surface 34,transverse to the pivot plane, which at least on a longitudinal sectiontowards the backrest 4 extends substantially straight. In the regionaway from the backrest 4, the head support surface 34 can run out,whereby there may be formed a transverse swelling 35 of the pad 21arranged in the associated end region.

The head support 7 can be adjusted into a child position illustrated inFIG. 3, in which the head support pad 21 is pushed directly or nearlyonto the backrest pad 4 c. In this position the head support surface 34in substance aligns with the shell base or with the back support surface36 of the backrest 4. Thereby, the head support surface 34 forms alargely transition-free continuation of the shell base of the backrest4, which preferably is likewise formed to be trough-shaped, in themanner of the shell, transversely of the pivot plane. In this childposition the shell base of the backrest 4 and the shell base of the headsupport 7 align with one another, through which the head of the child onthe treatment chair is advantageously supported. On the one hand due tothe head support surface 34 extending straight at least over alongitudinal section, and on the other hand due to the setting of thespacing of the back surface part 4 b from the backrest joint 5, therecan be attained an advantageous supporting of the head even withchildren of different sizes.

The backrest 4 has at its free end preferably a recess 37, into whichthe head support 7 can be moved, in particular for the child position.FIG 5 illustrates the head support 7 in the fully pushed downdisposition of the child position with the head support borne directlyagainst the backrest pad 4 c.

By means of the four adjustment motors V1 to V4 any desired position,required by the dentist, for all necessary kinds of treatment, can beattained. Thus it is possible for different kinds of treatment anddifferent persons to attain the ideal setting of the treatment chair 1.The child position according to FIG. 3 and an elevated rounded backposition can thus be set by means of motors.

By means of a program control, the adjustment motors are so programmedthat the head support movements and the movement of the backrest 4 areadapted to the anatomical movements of the patient, That is, at timestwo, three or four adjustment motors work simultaneously and carry outdifferent movement steps.

All four movements, two pivot movements and two longitudinal movements,are connected with a control unit via travel detectors. By these meansit is possible to electronically detect patient data for the dispositionon the patient chair, to store the data and then call it up again, uponthe next visit by the patient.

If by means of the program control the desired ergonomically ideal headpositioning is not attained, each of the four adjustment motors can beindividually activated by means of a switch and thus the ideal head/backpositioning attained.

1. Medical or dental treatment chair (1) comprising: a) a seat part (2),b) a back part (4), c) a carrier part (16) arranged on the back part(4), d) an intermediate lever (23) which has one end pivotably connectedin a first joint (24) with the carrier part (16), e) a head supportlever (27) which has one end pivotably connected in a second joint (25)to an opposite end of the intermediate lever (23), f) a head support pad(21) carried by the head support lever, g) an intermediate leveradjustment motor (M3) which is effective between the carrier part (16)and the intermediate lever (23), and h) a head support lever adjustmentmotor (M4) which is effective between the intermediate lever (23) andthe head support lever (27) i) wherein the adjustment motors (M3, M4)are linearly acting adjustment motors, j) whereby the intermediate leveradjustment motor (M3) is pivotably supported at one end at a workingspacing (V1) from the first joint (24) between the carrier part (16) andthe intermediate lever (23), k) wherein the intermediate leveradjustment motor (M3) pivotably engages the intermediate lever (23), l)whereby the head support lever adjustment motor (M4) is pivotablysupported at one end on the intermediate lever (23) at a workingdistance (V2) from the second joint (25), m) wherein the head supportadjustment motor (M4) pivotably engages an opposite end of the headsupport lever (27), n) wherein the head support lever adjustment motor(M4) engages on a transverse arm (23 c) of the intermediate lever (23),and o) whereby the transverse arm (23 c) is angled relative to theintermediate lever (23) towards the head support lever (27), in an endregion of the intermediate lever (23) adjacent the second joint (25). 2.Medical or dental treatment chair according to claim 1, wherein theopposite end of the intermediate lever adjustment motor (M3) engages inthe second joint (25).
 3. Medical or dental treatment chair according toclaim 1, wherein the head support lever (27) is formed with an angledtransverse arm (27 c) that is angled relative to the head support lever(27) towards the intermediate lever (23) in an end region adjacent thesecond joint (25).
 4. Medical or dental treatment chair according toclaim 1, wherein connection points between the adjustment motors (M3,M4) and the levers (23, 27) are joints (25, 31, 32, 33) preferablyhaving joint bolts which pass through associated joint eyes.
 5. Medicalor dental treatment chair according to claim 1, wherein the intermediateand head support levers (23, 27) each have at least two lever webs (23a, 27 a), respectively, at a transverse spacing from one another, andwhich are each respectively connected with one another by acorresponding transverse part (23 b, 27 b).